so ive had my v6 for about 7 years. it has 155XXX and theres a problem thats been having for a few years now. when the car is parked or in netural is seem fine. rpm, power, oil, temp, fuel gauges are fine. now once i change into drive the entire car shakes until i push the gas and go. once im in motion it runs like a dream.

of course once i slow down and make a full stop everything inside shakes, a very noticeable shake but now too violent or that its not going to turn off (trust me i know what it feels like when its about to shut off).

so what have i done: CAI, head gasket replaced with heads done, replaced water pump, just changed spark plug, some what new o2 sensors, changed spark plug wires, changed oil pump, changed radatior, put a big *** fan, no vacuum leak or water, changed IAC like 7 times, never changed the computer but i did put a mod on it a few years back but removed it.

so what do you guys think? could it be the transmission, i did replace one of the mounts on it. not too sure...

 

These is no way I can be sure what is going on without feeling it but based on your description you just have a idle issue. These can be caused by several different things. A EGR valve that will not seal, a gummed up IAC motor, a Small vacuum leak (normally feeding only one cylinder) even a semi clogged or dripping injector.

The normal way to track this down is a scope. It can be tuff to track down the issue without one. I would start by cleaning the IAC and EGR valve and making sure the EGR valve will seal, Then use carb cleaner and check for small vacuum leaks around the upper and lower intake.

Another thing you can try if you have access to habd held infared scanning type thermometer, Let the car idle (shake) for 10 minutes then check the temps at the exhaust manifold outlet at each cylinder. You are looking for one or two cylinder that are hotter or cooler then the rest. Hotter would mean vacuum leak or starving for fuel, Cooler would mean Not firing at all or very rich.

 

ok i have cleaned out the IAC and EGR (repalced the gasket as well). still the same. i will try the thermonmeter techinque. any other ideas.

 

what shape where the iac and egr in?

 

well to me they look good, i replaced the IAC about 4 months ago. i need a little more description.

 

Did you test the EGR for sealing?

 

sorry was it all crustied up with carbon and almost plugged, all black with a thick coat of black powdery stuff, black but not really coated in a layer thats thick, clean as though it was cleaned not long ago. hows that. lol.

 

You missed did it look shiny new?

 

lol yah and completely plugged.

 

Ok I just uploaded this on YouTube, check to hear the vibration when I change gears (automatic).